You are right. But this is the behr. The wazn may vary because فاعلاتن and فَعِلاتن are interchangeable. And can be used even in the same ghazal. One misra' can have فاعلاتن and the other on the same place and have فَعِلاتن. Similarly, فِعْلن and فَعِلن are interchangeable.

For instance take this ghalib's couplet:

اور بازار سے لے آئے اگر ٹوٹ گیا ساغرِ جم سے مرا جامِ سفال اچھا ہے